Four new species of Kinorhyncha from the Gulf of California, eastern Pacific Ocean

Abstract

Several meiofaunal samples from the central and lower Gulf of California were studied. Four new species of kinorhynchs, Cristaphyes fortis sp. nov., Higginsium mazatlanensis sp. nov., Cephalorhyncha teresae sp. nov. and Echinoderes xalkutaat sp. nov., are described herein. C. fortis sp. nov. may be distinguished from its most similar congeners by its more strongly developed pachycycli and ball-and-socket joints and the presence of unpaired paradorsal setae on segments 2, 4 and 6, two pairs of ventrolateral setae on segment 5, one pair of ventrolateral setae on segments 2–4, 6–7 and 10, and one pair of ventromedial setae on segments 8–9. H. mazatlanensis sp. nov. is easily distinguished from its congeners by the combined presence of subdorsal setae only on segment 1 and lateroventral setae only on even segments. C. teresae sp. nov. is unique within the genus by the presence of acicular spines in middorsal position on segments 4, 6 and 8, in sublateral position on segment 7 and in lateroventral position on segments 8 and 9, as well as tubes in subdorsal position on segment 2, and in lateroventral position on segment 5. Moreover, this species has primary pectinate fringes of segments 2–7 bearing a tuft of elongated spinous projections in middorsal position, which is unique among its congeners. E. xalkutaat sp. nov. belongs to a group of Echinoderes characterized by possessing type 2 glandular cell outlets in subdorsal, laterodorsal, sublateral and ventrolateral positions on segment 2, together with middorsal spines on segments 4–8, lateroventral spines on segments 6–9 and lateroventral tubes on segment 5, but the arrangement of the remaining type 2 glandular cell outlets (in midlateral position on segment 5, in sublateral position on segment 8 and in laterodorsal position on segment 10) and the cuticular composition of segment 11 (one tergal and two sternal plates) allow its morphological differentiation.